Conditions For Setting DTC

If the PCM detects a temperature difference of more than 27°F (915°C) between the ECT and the IAT, the vehicle must be driven for 5 minutes over 15 MPH. If the IAT decreases more than 12.6°F (7°C) then a block heater is indicated and the test is aborted. If the IAT temperature does not decrease, a block heater was not detected and this DTC will set.
The temperature difference between ECT and IAT at start-up is greater than 252°F (140°C).
The time spent cranking the engine, without starting is greater than 10 seconds.